The path to Soure Doomsday is littered with Flame Legion foes. Kill or skip them and make your way to the marker. Once you reach Soure, talk to him to trigger a cutscene.

Soure explains that he intended to kill the Flame Legion Shaman and acquire his magic, rather than joining the Flame Legion as he was falsely accused of. He will gladly join your warband once you eliminate the Flame Legion who are trying to press-gang Soure into joining their ranks. Head towards the marker and clear out the minor Flame Legion - after you clear them all out, Flame Recruiter Szagur appears. He is a veteran and uses AoE fire magic in addition to summoning many Embers, which makes the fight more difficult than it initially appears. Try to avoid standing in the AoE. Defeating the recruiter ends the mission and Soure joins your warband.

Clawspur: I'll just say it once and then it will be said—do we really want someone in our warband who once tried to join the Flame Legion?

Rytlock said he's loyal, and I trust the tribune's judgment.

Sure...but I trust yours even more.

Then follow my lead and we'll see for ourselves. Let's move.

That may just be a rumor. I want to meet Soure face-to-face before I decide.

Dinky: So this Soure guy really tried to join the Flame Legion? Can we trust him? They say the friend of my enemy is my enemy's friend. And the friend of my enemy's friend is my enemy's friend's friend.

Rytlock said he's loyal, so we're at least going to talk to him..

I just don't want to make a friend who's really an enemy... I mean make an enemy into a friend... ah, burn it all. Let's just make sure he's a good guy, okay?

I will. Let's go.

That's what we're here to find out. Let's move.

Euryale: Is this worth it? The last thing we need is another spellcaster who wants to be Flame Legion. Makes the rest of us magic-users look bad.